If it's a fresh install where did you put the driver?
I am guessing vyper got lucky and had a 2.0 on his board and plugging it into that one worked..
Tried all my usb ports and no go.. err checked ASUS all usb are 3.0...
The usb dvd is 2.0 and so is the stick...
What is the work around for the Asus z270 AR?
Go to Asus website and download the drivers and put it on the same USB drive you have the Windows ISO, should work. Google ASUS clean install with no 3.0 usb support, I am sure it will come up.